The present invention relates to a method and a machine for reproducing a reproduction picture from an original picture by scanning, and, more particularly, relates to a method and a machine for reproducing a reproduction picture from an original picture by scanning, in which a light spot scans the original picture, and from this light spot is produced an analog original picture signal, and this analog original picture signal is broken down into a plurality of separation picture signals which, after digitalization, are stored in a memory. Then from the memory are read out digital reproduction picture signals, which are converted into analog signals and either are used to record a plurality of reproduction pictures, or are combined so as to record a combined reproduction picture. In such a system, the present invention offers a way in which the capacity required for the memory can be reduced.
It has been practiced heretofore to carry out such a method by a layout scanner. A plurality of color original pictures are scanned to produce an original picture analog signal, and this signal is then separated into, for example, red, green, and blue color separation analog signals. Then these color separation analog signals are converted into color separation digital signals in an analog/digital converter. The digitalized color separation signals are stored in a memory. Then, depending upon the desired layout positions, digital color separation picture reproduction signals are read out of the memory, and then these are converted into analog color separation reproduction signals of yellow, magenta, cyan, and black colors in a digital/analog converter. These signals are then used to modulate a recording light beam, and thereby color separation pictures are obtained as laid out in the desired positions on a recording film.
However, such a method involves a memory which has a large capacity. For instance, if an original color picture with a size of 250 .times.250 mm is scanned at a scanning density of 20 lines per mm, altogether there are obtained (20.times.250).sup.2 =25 million picture elements. If therefore the picture signals are broken down into red, green, and blue signals, there are required three times as many storage locations in the memory, i.e. 75 million, and if the picture signals are broken down into yellow, magenta, cyan and black signals, there are required four times as many storage locations in the memory, i.e. a hundred million. Thus, if the number of levels for each color signal is set to 256, so that each color signal stored in the memory requires one byte, or eight bits, then a memory with a capacity of 75 or 100 megabytes is required. If, further, several original pictures are scanned in a single scanning operation, and the picture signals for them all are stored together in the memory, then the size required for the memory further increases. This is what is required in a layout scanner: it is necessary to store picture signals for each separation color for the entire area of each original picture. Further, the memory has to be capable of responding at a high speed, and has to be random-access. Therefore the cost becomes high, and the size of the total picture area which can be handled is limited.